Approach:
Our approach incorporates a comprehensive and multidisciplinary strategy that combines selective breeding, functional genomics of pathogenic bacteria, development of genetic markers associated with health traits and immunological studies. In the first objective, we utilize conventional family-based selective breeding to increase bacterial cold water disease resistance and evaluate select and control fish performance in on-farm trials. In the second objective, we characterize indicators of virulence in emerging strains of vaccine-resistant Y. ruckeri using molecular and genomic approaches and develop novel therapeutics to treat or prevent bacterial disease. In the third objective, we identify genes and non-genetic factors in trout that are critical to expression of innate and acquired immune responses using molecular and immunological techniques. We will identify and measure mucosal immune system function and dietary immunomodulation of local immunity. The overall impact of this research is improved animal well-being, reduced antibiotic use and increased production efficiency.